Compilare: user.cpp: In function ‘void DF(int)’: user.cpp:15:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[nod].size (); i++) ^ user.cpp:23:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v.size (); i += 2) { ^ user.cpp: In function ‘int main()’: user.cpp:32:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("g2mm.in", "r", stdin); ^ user.cpp:33:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("g2mm.out", "w", stdout); ^ user.cpp:35:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d\n", &n, &m); ^ user.cpp:39:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d\n", &x, &y); ^